Norbornadiene
Structural formula | ||||||||||||||||
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General | ||||||||||||||||
Surname | Norbornadiene | |||||||||||||||
other names |
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Molecular formula | C 7 H 8 | |||||||||||||||
Brief description |
light yellow liquid |
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properties | ||||||||||||||||
Molar mass | 92.14 g mol −1 | |||||||||||||||
Physical state |
liquid |
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density |
0.91 g cm −3 |
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Melting point |
−19 ° C |
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boiling point |
90 ° C |
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Vapor pressure |
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solubility |
practically insoluble in water |
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Refractive index |
1.470 (20 ° C) |
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safety instructions | ||||||||||||||||
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Toxicological data | ||||||||||||||||
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
Norbornadiene is a bicyclic hydrocarbon that is being discussed as a potential candidate for storing solar energy . It is also of interest as a metal ligand that is used in homogeneous catalysis . Norbornadiene is also a useful dienophile in the Diels-Alder reaction . Related bicyclic compounds are norbornene , which has the same carbon structure but only one double bond, and norbornane , also with the same structure, but without double bonds and thus saturated.
synthesis
Norbornadiene can be produced by the reaction of cyclopentadiene and acetylene .
properties
Norbornadiene forms highly flammable vapor-air mixtures. The compound has a flash point of around −11 ° C. The explosion range is between 1% by volume (38 g / m 3 ) as the lower explosion limit (LEL) and 6.3% by volume as the upper explosion limit (UEL). The ignition temperature is 350 ° C. The substance therefore falls into temperature class T2.
Storage of solar energy
Quadricyclane , a valence isomer , can be obtained by photochemical isomerization in the presence of a sensitizer such as e.g. B. Michler's ketone or acetophenone can be obtained.
This pair of isomers is of potential interest for the storage of solar energy if the reverse reaction is possible through a controlled process. Theoretically storable energy is −89 kJ / mol. Since the main absorption of this reaction is around 300 nm, but only small portions of the sunlight are below 400 nm, this use is limited.
Reactions
Norbornadiene is a reactive reagent in cycloadditions and also a starting material for the production of diamond and sumanes . It is also used as an acetylene transfer agent in reactions with tetrazines such as 3,6-di-2-pyridyl-1,2,4,5-tetrazine .
Use as a ligand
Norbornadiene is a versatile ligand in organometallic chemistry where it acts as a two- or four- electron donor .
An example of this is tetracarbonyl (norbornadiene) chromium (0).
literature
- Beyer / Walter : Textbook of Organic Chemistry , 19th edition, S. Hirzel Verlag, Stuttgart 1981, ISBN 3-7776-0356-2 , p. 390.
- Streitwieser / Heathcock : Organic Chemistry , 1st edition, Verlag Chemie, Weinheim 1980, ISBN 3-527-25810-8 , pp. 1351-1352.
Web links
Individual evidence
- ↑ a b c data sheet bicyclo [2.2.1] hepta-2,5-diene, 98% from Sigma-Aldrich , accessed on March 13, 2014 ( PDF ).
- ↑ a b c d e f g h i j k l m Entry on bicycloheptadiene in the GESTIS substance database of the IFA , accessed on November 28, 2017(JavaScript required) .
- ↑ a b c d e Entry on Norborna-2,5-diene. In: Römpp Online . Georg Thieme Verlag, accessed on November 28, 2017.
- ↑ Claibourne D. Smith: Quadricyclane In: Organic Synthesis . 51, 1971, p. 133, doi : 10.15227 / orgsyn.051.0133 ; Coll. Vol. 6, 1988, p. 962 ( PDF ).
- ↑ AD Dubonosov, Vladimir A. Bren, VA Chernoivanov: Norbornadienes - quadricyclane as to abiotic system for the storage of solar energy. In: Russian Chemical Reviews 71 (2002): 917-927.
- ↑ Gregory W. Sluggett, Nicholas J. Turro, Heinz D. Roth: Rh (III) -Photosensitized interconversion of norbornadiene and Quadricyclane . In: J. Phys. Chem. A . 101, No. 47, 1997, pp. 8834-8838. doi : 10.1021 / jp972007h .
- ↑ Constantine Philippopoulos, Dimitrios Economou, Constantine Economou, John Marangozis: Norbornadiene-Quadricyclane System in the Photochemical Conversion and Storage of Solar Energy . In: Ind. Eng. Chem. Res . 22, No. 4, 1983, p. 627. doi : 10.1021 / i300012a021 .
- ↑ Tamara M. Gund, Wilfried Thielecke, Paul v. R. Schleyer: Diamantane In: Organic Syntheses . 53, 1973, p. 30, doi : 10.15227 / orgsyn.053.0030 ; Coll. Vol. 6, 1988, p. 378 ( PDF ).
- ↑ Ronald N. Warrener, Peter A. Harrison: π-Bond Screening in Benzonorbornadienes: The Role of 7-Substituents in Governing the Facial Selectivity for the Diels-Alder Reaction of Benzonorbornadienes with 3,6-Di (2-pyridyl) -s -Tetrazine . In: Molecules . 6, No. 4, 2001, pp. 353-369. doi : 10.3390 / 60400353 .
- ↑ Ryo Shintani, Tamio Hayashi: Chiral Diene Ligands for Asymmetric Catalysis , Aldrichimica Acta , 2009, vol. 42, number 2, pp. 31-38.
- ↑ Markus Strotmann, Rudolf Wartchow, Holger Butenschön: High yield synthesis and structures of some achiral and chiral (diphosphine) tetracarbonylchromium (0) chelate complexes with tetracarbonyl (norbornadiene) chromium (0) as complexation reagent . In: Arkivoc . 2004, pp. KK-1112F.